Is It Possible To Define A Type For All It's Elements?
Sep 21, 2009
I'm using the Hashtable class for the first time, and have a question about it:Is it possible to define a type for all it's elements? So that when you for example only put strings in it, you can retrieve them without having to cast them from objects.
I wanted to define a property which accepts decimal numbers and do some process on the value and return string such as the below:
Public Property Amount() As String Get Return Utility.PaddingRight(Me.msAmount.ToString(), 10) End Get
[code]....
But compilers warns "Set parameters must have the same type of the containing property."It doesn't look like it should throws an error since it looks legit.
I have a list(of object) lets say ob1,ob2,ob3 that are classes I want to write a linq-querry that exstract from this list only one particolur object that is different time to time how can I write the linq querry?
dim List as new list(of Object) list.add(ob1) list.add(ob2) list.add(ob3) dim Result=(from P as ob3.gettype in list select p).tolist
Im trying to grasp session varibles, i understand what they are etc but i would like to know how to define a type for each session variable.Iv written it like this
Session("Title") = txtTitleContent.Text
How can i tell it what type of value is going to be in it, because at the moment im only playing about with strings, but what if i have an integer and want to pass it back to the back end to save it will throw an error saying "conversion from string to integer is not valid" should i use Cint to deal with this?
I'd like to create a user-defined data type in VB.NET but don't know how to do it.Take an example.......say there's a variable to control the action of a timer control. The possible actions would be "no action", "run timer", and "stop timer."I could do this with an integer (e.g. 0=no action, 1=run timer, 2=stop timer), but I'd rather create a data type so that the options are more explanatory than a simple integer. Like so....
Private Timer_Action as MyDataType Timer_Action=MyDataType.RunTimer
I am trying to rewrite an ap I wrote in Vb6 to VBNet 2008. Part of requires signing in to a website automatically. [Code] Can some tell me what data type I need for the form elements? I have tried HTMLELEMNT but that doesn't let me change the value or click.
I am trying to redirect command line output to a list box in a vba macro, and I've found some code that I think might point me in the right direction, but I keep on getting the same error. When I use this code [code]It gives me the error in the title and highlights the first declaration line.What does it take to define a new "process".
I created a method and pass the element type, id, and any inner text that instantiates a new html element. The last statement: Me.Controls.Add(element) adds it to the end of the page, but I would like it to be inserted in a specific position (between 2 divs within a form). What I am describing is very similar to this post on SO here, although it was for javascript.
I am using System.Reflection to load a type that I cannot otherwise load during design time. I need to pull all controls within a collection of this type, however, i the OfType command doesn't seem to like the reflection Syntax. here is "close to" what I got.
Dim ControlType As Type = System.Reflection.Assembly.GetAssembly( _ GetType(MyAssembly.MyControl)) _ .GetType("MyAssembly.MyUnexposedControl") Dim Matches as List(Of Control) = MyBaseControl.Controls.OfType(Of ControlType)
So that code is bogus, it doesn't work, but you get the idea of what I am trying to do. So is there a way to use reflection and get all of the controls that are of that type?
i wonder if it's possible to define a variable/property of more than one type. Let's say i want a property TextWebControl that is a WebControl and also implements Web.UI.ITextControl(f.e. like a TextBox or Label). But i don't want to enforce that it is a TextBox or Label, but only one that inherits from WebControl and also implements ITextControl so that it also would work with controls added in future releases of .Net-Framework.
.Net-Framework 4.0
Edit: I have retagged the question and added VB.Net because it's my default language. Normally it's no problem for me to understand C# also, but i must admit that it's difficult to translate generic stuff to VB.Net without experiences and it's also better documentated in C# than in VB. So i would appreciate(and aceept) a working example of a VB.net generic type of ITextControl/WebControl.From Marc's answer i understand that i need a generic class. But how do i instantiate it in SomeClass? This won't compile:
Class SomeClass Public Property info As InfoControl(Of WebControl, ITextControl) End Class Public Class InfoControl(Of T As {WebControl, ITextControl}) End Class
Is there any way to define a Generic in VB.NET which will accept only Singles or Doubles? I tried the following things, based on what I've found online, but none compile:
Dim target As Nullable(Of {Single, Double}) Dim target As Nullable(Of T As {Single, Double}) Dim target As Nullable(Of T {Single, Double}) Dim target As Nullable(Of Single, Double) Dim target As Nullable(Of T As Single, Double)
I want to specify that target can either be a Single? or a Double? only.
I have a class called "heater". One of the properties is "designstatus", a string. I want to limit the property to one of three choices; "current", "obsolete", "notdesigned".
How to define array in vb2005? (Actually, I am making a game, whcih have to find out a pair of same pictures. I want to randomize 8 pictures, but it will randomize some pictures which is the same. Therefore, I need to use array.
I need to do something like this Class A End Class Class B Inherit A End Class A=B If i try i get an exception! that i can not cast B in A. How can I overcome this problem? I need to define 2 classes B identical to A but as a distinct class What I need is to be able to cast one class to the other like A=B or B=A I tried with directcast but i got the exception what can I do
I know to define integer type sqlparameter but I do not know the decimal type sqlparameter for the precession.
I am giving a sample example.
//Code Dim sqlparameters(2) as sqlparameter sqlparameters(0)=new sqlparameter ("@RMID", SqlDbtype.integer,7) but in case of decimal I am giving like this sqlparameters(1)=new sqlparameter ("@RMID", SqlDbtype.decimal,7,2) which is wrong
I have no idea as to how I can define a variable as "GLOBAL" in VB Express 2008. I used VB V 3.0 and if I remember correctly the statement "Global varName as Integer" allowed me to use the variable across different forms. I've tried the statement "Public varName as Integer = 0" on Form1 but Form2 tells me the variable is not declared.
The statement (in Form1) "Form2.Label1.Text = CStr(varName)" displays the value on Form2 in Label1 but I cannot then use the value again in Form2, e.g. "Label2.Text = Label1.Text". How I can transfer a variable value from one form to another and manipulate that variable in the second form?
I have remplace the keyarr definition by my SQL query: With the code above, I can print both keyarr in a console. What should I change in the _sqlReader.Read() function in order to get keyarr definition like the first code. I would like that keyarr could be interpreted by the rest of my code.
I need to define Virtual IP programmatically (Perl or VB or CMD or java).I need it for temporary use, I can't use any actual IP address and I don't care if it will be accessible only from local machine.
What is that 0x thingy notation ALso what is &H notation Sometimes I see 0& when calling API what does that mean?What's the difference between 0& and 0
I am making an interface that has a number of events defined in it. When I implement the interface in a class the events will show up. I want to force a class that implements my interface to also have to make the event handlers too. I don't care where the class raises the event, but I want them to have to define what happens once the event is raised. Is this possible and if so, how do I do it?
In java I use the Desktop application as under;Create JFrame Add JdesktopPane and in the Jframe constructor intilize the all the child forms and then in the events i use child form.visible method.But in the VB where is best technoque to use child forms to initilize?i also need a piece of code for the application to learn how effectively i use the VB to develop MDI application.
I often have a class defined and I also define another class that is simply a collection of the other class. To do this I found it easiest just to define the other class as Inherits List(Of Type). The reason I define a collection class is to add extra functionality to the collection. Take the following code for example.
Class Car Property Name As String Property Year As Short
[Code]....
how can I define my own collection so that I can reference it by index or name like that. Right now I can only reference it by index.